As wireless technology has advanced, a variety of different types of wireless networks have been installed, such as cellular and other wireless networks. Some wireless networks are based upon the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of Wireless LAN (WLAN) industry specifications, for example. Other wireless technologies are being developed, such as IEEE 802.16 or WiMax industry specifications. IEEE 802.16 defines the Wireless MAN air interface specification for wireless metropolitan area networks. A number of working groups are working to continually improve this technology.
One proposed amendment to the 802.16 specification is the implementation of bidirectional transmit and receive zones for relay stations (RSs) implemented in 802.16 networks. In a RS bidirectional transmit zone, a RS would simultaneously transmit upstream to a superordinate station (e.g., base station or other RS) and transmit downstream data to its subordinate stations (e.g., one or more mobile stations and/or other RSs).
Similarly, in a RS bidirectional receive zone, a RS would simultaneously receive downstream data from its superordinate station and receive upstream data from its subordinate stations. However, implementation of such RS bidirectional zones violates the time division duplex synchronization for data frames transmitted in 802.16 networks.